JPH07243838A - Method of measurement of surface layer thickness of multi-layered material - Google Patents
Method of measurement of surface layer thickness of multi-layered materialInfo
- Publication number
- JPH07243838A JPH07243838A JP6035062A JP3506294A JPH07243838A JP H07243838 A JPH07243838 A JP H07243838A JP 6035062 A JP6035062 A JP 6035062A JP 3506294 A JP3506294 A JP 3506294A JP H07243838 A JPH07243838 A JP H07243838A
- Authority
- JP
- Japan
- Prior art keywords
- surface layer
- layer thickness
- gain amplifier
- amplifier
- thickness
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Links
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- Length Measuring Devices Characterised By Use Of Acoustic Means (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】この発明は、クラッド鋼など表層
と内層で組成や組織が異なる複層材料の表層厚さを超音
波により効率良く正確、かつ確実に検出し、また複層材
料の表面が平滑でない場合に於ても効率良く正確、かつ
確実に検出することができる複層材料の表層厚さ測定方
法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is capable of detecting the surface layer thickness of a multi-layer material such as clad steel having a different composition and structure between the surface layer and the inner layer by ultrasonic waves efficiently and accurately and surely, and also for detecting the surface of the multi-layer material. The present invention relates to a method for measuring the surface layer thickness of a multi-layer material, which enables efficient, accurate and reliable detection even when is not smooth.
【０００２】[0002]
【従来の技術】複層鋼板は、耐食性、耐摩耗性などが優
れた表層材を用いることで、内層材が持つ加工性、靭性
を損なうことなく耐久性を持たせた鋼材である。これら
の鋼材の耐食性、耐摩耗性などはその表層厚さに密接に
関連しているために、必要充分な表層厚さがあることを
保証することが、不可欠である。そのために何らかの方
法により、層厚さを非破壊的に測定することが必要不可
欠であり、超音波パルス反射法による測定が一般的に用
いられている。この複層鋼板の超音波パルス反射法によ
る表層厚さ測定法については、日刊工業編「超音波探傷
法」（１９９７年改定新版）Ｐ５２２−に開示されてい
る。2. Description of the Related Art A multi-layer steel sheet is a steel material which is made durable by using a surface layer material having excellent corrosion resistance and wear resistance without impairing the workability and toughness of the inner layer material. Since the corrosion resistance, wear resistance, etc. of these steel materials are closely related to the surface layer thickness, it is essential to ensure that the surface layer thickness is necessary and sufficient. Therefore, it is indispensable to measure the layer thickness non-destructively by some method, and the ultrasonic pulse reflection method is generally used. The method for measuring the surface layer thickness of the multi-layer steel sheet by the ultrasonic pulse reflection method is disclosed in “Ultrasonic flaw detection method” (ed.
【０００３】この方法を用いるには界面からの充分な反
射エコーが得られることが必要であり、ごく一般的な複
層鋼板の場合、例えば表層はＳＵＳ３０４材のようなオ
ーステナイト系ステンレス鋼、内層はＳＭ４００のよう
な鋼材の場合、界面からの超音波の反射率は１％程度と
かなり大きいために、容易に界面エコーが得られ、層厚
さ測定が可能である。In order to use this method, it is necessary to obtain a sufficient reflection echo from the interface. In the case of a very general multi-layer steel sheet, for example, the surface layer is austenitic stainless steel such as SUS304 material, and the inner layer is In the case of a steel material such as SM400, the reflectance of ultrasonic waves from the interface is as large as about 1%, so that an interface echo can be easily obtained and the layer thickness can be measured.
【０００４】しかし、近年、連続鋳造時に直接複層鋼材
を造り、そのまま圧延して複層鋼板とする新製造法が開
発され、似通った組織や組成の鋼種を組み合せた複層鋼
板を容易に製造することが可能となった。この様な鋼材
では表層と内層で組成、組織が似通っているため界面で
の反射率が非常に小さくなり、そのために界面エコーも
非常に小さいものとなり、検出が困難となる。However, in recent years, a new manufacturing method has been developed in which a multi-layer steel product is directly produced during continuous casting and rolled as it is to produce a multi-layer steel plate, and a multi-layer steel plate combining steel types having similar structures and compositions can be easily manufactured. It became possible to do. In such a steel material, the composition and structure of the surface layer and the inner layer are similar, so the reflectance at the interface is very small, and therefore the interface echo is also very small, making detection difficult.
【０００５】上記課題を解決し、より効率良く正確、か
つ確実に検出する方法として、本発明者らは、特願平５
−０９１６０１号において、表面エコーを検出するため
には、低利得アンプを設けその低利得アンプからの出力
信号があらかじめ設定しておいたスレッシュホールドを
越える位置を特定し、また界面エコーを検出するために
は、更に低利得アンプの出力信号を高利得で増幅し、そ
の高利得アンプからの出力信号があらかじめ設定してお
いたスレッシュホールドを越える位置を特定し、それら
２つの特定した位置の時間差から表層厚さを測定すると
いう、２段階にアンプを設けることにより超音波パルス
反射法を改良する方法を提案した。As a method for solving the above problems and detecting more efficiently, accurately and surely, the inventors of the present invention have proposed Japanese Patent Application No.
In No. 0911601, in order to detect a surface echo, a low gain amplifier is provided to specify a position where an output signal from the low gain amplifier exceeds a preset threshold, and also to detect an interface echo. In addition, the output signal of the low gain amplifier is further amplified with high gain, the position where the output signal from the high gain amplifier exceeds the preset threshold is specified, and from the time difference between these two specified positions, We proposed a method of improving the ultrasonic pulse reflection method by providing an amplifier in two stages, that is, measuring the surface layer thickness.
【０００６】[0006]
【発明が解決しようとする課題】図４に示す、従来の超
音波パルス反射法を改良した２段階のアンプを設ける方
法では、低利得アンプの出力信号１７を、界面エコーを
得るために、更にかなりの高利得で増幅するために、図
５に示すように高利得アンプからの出力信号１８はかな
りＳ／Ｎ比が悪く、高利得アンプの出力信号に対して、
信号の立上りを読み取るためのスレッシュホールドをど
のレベルに設けるかが非常に困難となるばかりでなく、
時としてノイズレベルが設定しておいたスレッシュホー
ルドを越えることがあり、測定ミスの原因となる。In the method of providing a two-stage amplifier which is an improvement of the conventional ultrasonic pulse reflection method shown in FIG. 4, the output signal 17 of the low gain amplifier is further obtained in order to obtain the interface echo. In order to amplify with a considerably high gain, the output signal 18 from the high gain amplifier has a considerably poor S / N ratio as shown in FIG.
Not only becomes it very difficult to set the threshold for reading the rising edge of the signal,
Sometimes the noise level may exceed the set threshold, causing measurement errors.
【０００７】また、連続鋳造時に直接複層鋼材を造り、
そのまま圧延して複層鋼板とする新製造法においては、
早期時期に製造工程へ表層厚さ情報を提供するニーズが
高く、スラブ段階での表層厚さ測定が必要となってい
る。しかし、スラブでは表面のオシレーションマークの
ために、図５に示すように表面エコーが乱れてしまい、
層厚さ測定に必要不可欠な表面エコーのスレッシュホー
ルドレベルの設定、立上り位置の特定が非常に困難とな
るばかりではなく、界面エコーも表面での音波の散乱の
ために、さらに小さくなり測定が不可能となる。Further, during continuous casting, a multi-layer steel material is directly produced,
In the new manufacturing method of rolling as it is to a multilayer steel sheet,
There is a strong need to provide surface thickness information to the manufacturing process at an early stage, and it is necessary to measure the surface thickness at the slab stage. However, in the slab, the surface echo is disturbed as shown in FIG. 5 due to the oscillation mark on the surface,
Not only is it very difficult to set the threshold level of the surface echo and the rising position that are indispensable for layer thickness measurement, but also the interface echo becomes even smaller due to the scattering of sound waves on the surface, which makes the measurement impossible. It will be possible.
【０００８】本発明は上記事情に鑑みてなされたもので
あり、表層と内層で組成や組織が似通った複層材料の表
層厚さを表面が平滑でない場合に於ても、超音波反射法
により効率良く正確に、かつ確実に検出する方法を提供
することを目的とする。The present invention has been made in view of the above circumstances. Even when the surface layer of a multi-layer material having a similar composition and structure in the surface layer and the inner layer is not smooth, the ultrasonic reflection method is used. It is an object of the present invention to provide a method for detecting efficiently, accurately and surely.
【０００９】[0009]
【課題を解決するための手段】本発明は、上記の目的を
達成するために、超音波を送信する送信器と、超音波探
触子と、探触子の出力信号を増幅するアンプが、低利得
のアンプと、その出力に時間ゲートをかけたのち高利得
で増幅するアンプを備えた表層厚さ測定手段を用いた複
層材料の表層厚さ測定方法において、測定しようとする
試料の表層材と同一材質、かつ表層厚さとほぼ同一厚さ
の表面の滑らかな単相材から、前記低利得アンプを用い
予め採取した表面の信号を低アンプ用参照データ、裏面
の信号を高利得用参照データとしてデジタル化して保存
しておき、被測定試料に対する低利得アンプ、高利得ア
ンプの出力をそれぞれデジタル化して、それぞれに対応
した前記参照データとの相関関数計算をそれぞれに行
い、それらの最大値を示す時間の差と、予め求めてある
音速を掛けて表層厚さを求めることを特徴とする複層材
料の表層厚さ測定方法方法を提供するものである。In order to achieve the above object, the present invention provides a transmitter for transmitting an ultrasonic wave, an ultrasonic probe, and an amplifier for amplifying an output signal of the probe. In the surface layer thickness measuring method for a multilayer material using a surface layer thickness measuring means equipped with a low gain amplifier and an amplifier for amplifying with high gain after applying a time gate to the output, the surface layer of the sample to be measured Material is the same material, and the surface thickness is almost the same as the thickness of the surface, and the smooth surface of the single-phase material is sampled beforehand using the low gain amplifier. It is digitized and stored as data, the outputs of the low gain amplifier and high gain amplifier for the sample to be measured are digitized, and the correlation function calculation with the reference data corresponding to each is performed respectively, and their maximum values The difference between the time indicated, is intended to provide a surface layer thickness measurement method The method of the multi-layer material and obtaining a surface layer thickness multiplied by the speed of sound are calculated in advance.
【００１０】また、請求項１において、前記相関関数か
ら最大値を示す時間を求める方法が、相関関数計算によ
り得られた２つの関数に対し、それぞれの関数の絶対値
を取り、絶対値を取った２つの関数のそれぞれの包絡曲
線を計算し、それらの最大値を示す時間の差と、予め求
めてある音速を掛けて表層厚さを求めることを特徴とす
る複層材料の表層厚さ測定方法を提供するものである。According to the first aspect of the present invention, the method for obtaining the time at which the maximum value is obtained from the correlation function is to take the absolute value of each of the two functions obtained by the correlation function calculation, and take the absolute value. The surface layer thickness of a multi-layer material is calculated by calculating the envelope curve of each of the two functions, and multiplying the difference in time showing the maximum values of them with the speed of sound obtained in advance to determine the surface layer thickness. It provides a method.
【００１１】[0011]
【作用】本発明に係る複層材料の表層厚さ測定方法は、
上記構成により超音波パルス波、または超音波バースト
波の反射波を使用し、相関関数を用いることで表層厚さ
を測定することとした。The function of measuring the surface layer thickness of the multilayer material according to the present invention is as follows.
With the above configuration, the reflected wave of the ultrasonic pulse wave or the ultrasonic burst wave is used, and the surface layer thickness is measured by using the correlation function.
【００１２】まず、高利得、低利得アンプからの出力信
号を別々にＡ／Ｄ変換ボードを介してデジタル信号とし
て計算機に取り込む。高感度の測定では鋼材の中心偏析
などに起因する散乱エコーが板厚の４分の１から板厚中
心付近まで発生し、界面エコーと誤判断しないように板
表面から中心偏析などに起因する散乱エコーの手前まで
の受信信号をＣＲＴ画面を見ながら取り出す。低利得ア
ンプからの出力信号と該出力に対応する低利得アンプ用
参照データとの相関の強い場所を、相関関数計算を行う
ことにより、該関数の最大値の位置を見つけることで、
表面エコーのスレッシュホールドの設定を行わずに、特
定することができる。また、該高利得アンプからの出力
信号と該出力に対応する高利得アンプ用参照データとの
相関の強い場所を、相関関数計算を行い最大値の位置を
見つけることで、スレッシュホールドの設定を行わずに
界面エコーを特定することができる。上記２つの相関関
数の最大値間の時間差を、あらかじめ測定しておいた板
内での縦波の音速で換算し、表層厚さを測定することで
精度よく複層材料の表層厚さ測定することが可能となっ
た。First, the output signals from the high-gain and low-gain amplifiers are separately taken into the computer as digital signals via the A / D conversion board. In high-sensitivity measurement, scattering echoes due to center segregation of steel materials occur from a quarter of the plate thickness to near the center of the plate thickness, and scattering due to center segregation from the plate surface is avoided so as not to be mistaken for interface echo. Take out the received signals up to the point before the echo while looking at the CRT screen. By finding the position of the maximum value of the function by performing a correlation function calculation on a place where the correlation between the output signal from the low gain amplifier and the reference data for the low gain amplifier corresponding to the output is strong,
It can be specified without setting the threshold of the surface echo. Further, the threshold is set by performing a correlation function calculation and finding the position of the maximum value at a location where the correlation between the output signal from the high gain amplifier and the high gain amplifier reference data corresponding to the output is strong. The interface echo can be identified without the need. The time difference between the maximum values of the above two correlation functions is converted into the sound velocity of the longitudinal wave in the plate measured in advance, and the surface layer thickness is measured to accurately measure the surface layer thickness of the multilayer material. It has become possible.
【００１３】また、相関関数計算により得られた２つの
関数に対し、更にその各々の関数の絶対値を取り、絶対
値を取った２つの関数の各々の包絡曲線を計算する手段
を設け、各々の包絡曲線の最大値間の時間差から表層厚
さを測定することにより、界面での位相の反転を気にす
ることなく、また散乱などの波の干渉より生じる相関関
数曲線の乱れを軽減でき、より精度よく複層材料の表層
厚さ測定することが可能となった。Further, for the two functions obtained by the correlation function calculation, means for calculating the absolute value of each function and calculating the envelope curve of each of the two functions for which the absolute value is calculated are provided. By measuring the surface layer thickness from the time difference between the maximum values of the envelope curve of, without disturbing the phase reversal at the interface, it is possible to reduce the disturbance of the correlation function curve caused by the interference of waves such as scattering, It has become possible to more accurately measure the surface layer thickness of multi-layer materials.
【００１４】[0014]
【実施例】本発明の装置構成の一例を図１に示す。ま
た、本発明方法の動作を説明するためのタイムチャート
を図２に示す。複層鋼板１は板厚２００mmで、内層材９
は普通鋼、表層材１０，１１はＮｉ系ＳＵＳ材で平均的
表層厚さは各々２０mmのオシレーションマークのあるス
ラブとする。あらかじめ水没させておいた複層鋼板１に
対して、探触子２は送信器３によって５MHz の超音波バ
ースト波を３周期分発信する。超音波は水中および鋼中
を経路１５、１６の様に伝播し、再び探触子２で受信さ
れる。FIG. 1 shows an example of the apparatus configuration of the present invention. A time chart for explaining the operation of the method of the present invention is shown in FIG. The multi-layer steel sheet 1 has a plate thickness of 200 mm and the inner layer material 9
Is ordinary steel, and the surface layer materials 10 and 11 are Ni-based SUS materials, and the average surface layer thickness is a slab with oscillation marks of 20 mm each. The probe 2 transmits the ultrasonic burst wave of 5 MHz for 3 cycles by the transmitter 3 to the multi-layered steel plate 1 which has been submerged in advance. The ultrasonic wave propagates in water and in steel as paths 15 and 16, and is received by the probe 2 again.
【００１５】本方法では、探触子２で受信された超音波
信号は低利得アンプ４にて増幅される。低利得アンプ４
の出力１７はＡ／Ｄ変換ボード６によりデジタル信号に
変換され、デジタル信号Ａ1 （ｔ）２７となる。In this method, the ultrasonic signal received by the probe 2 is amplified by the low gain amplifier 4. Low gain amplifier 4
Output 17 is converted into a digital signal by the A / D conversion board 6 and becomes a digital signal A 1 (t) 27.
【００１６】一方、低利得アンプ４の出力１９はさらに
高利得アンプ５に導入される。ここで、高利得アンプ５
は高い利得の増幅器であり、高利得の信号では鋼材の中
心偏析などに起因する散乱エコーが板厚の４分の１から
板厚中心付近まで発生するため、界面エコーと誤判断し
易い。そのため、表面エコー後方から中心偏析などに起
因する散乱エコーの手前までの信号のみを禁止ゲート２
１を設けることで取り出す。高利得アンプ５からの出力
１８はＡ／Ｄ変換ボード７によりデジタル信号Ａ
2 （ｔ）２９に変換される。本実施例の場合、平均表層
厚さが２０mm程度であるので、表面エコーの後方から板
厚約５分の１部分までの受信信号３ｋワード（サンプリ
ング周波数２００Ms／s ）を、信号Ａ2 （ｔ）２９とし
て取り出す。On the other hand, the output 19 of the low gain amplifier 4 is further introduced into the high gain amplifier 5. Here, the high gain amplifier 5
Is a high-gain amplifier, and in the case of a high-gain signal, scattered echoes caused by segregation of the center of the steel material are generated from a quarter of the plate thickness to near the center of the plate thickness, so that it is easy to erroneously determine it as an interface echo. Therefore, only the signal from the back of the surface echo to the front of the scattered echo due to center segregation is prohibited.
It is taken out by providing 1. The output 18 from the high gain amplifier 5 is converted into a digital signal A by the A / D conversion board 7.
2 (t) 29. In the case of the present embodiment, since the average surface layer thickness is about 20 mm, the received signal 3 k words (sampling frequency 200 Ms / s) from the back of the surface echo to about 1/5 of the plate thickness is converted into the signal A 2 (t ) Take out as 29.
【００１７】また、予め表層材（Ｎｉ系ＳＵＳ材）１０
と同材質で縦１００mm、横１００mmで厚さが２０mmの研
摩された試料を用い、表面エコーを図３（ａ）の低利得
アンプ用参照波形ｈ1 （ｎ）（表面エコー）３３とし
て、底面エコーを図３（ｂ）の高利得アンプ用参照波形
ｈ2 （ｎ）（界面エコー）３４として低利得アンプと同
程度の増幅率で１μｓ（２００ワード）を保存部２３に
蓄積しておく。Further, a surface layer material (Ni type SUS material) 10 is previously prepared.
Using a polished sample of the same material as that of 100 mm in length, 100 mm in width and 20 mm in thickness, the surface echo is used as the reference waveform h 1 (n) (surface echo) 33 for low gain amplifier of FIG. The echo is used as the high gain amplifier reference waveform h 2 (n) (interface echo) 34 of FIG. 3B, and 1 μs (200 words) is stored in the storage unit 23 at an amplification factor similar to that of the low gain amplifier.
【００１８】該低利得アンプからの出力信号と該信号に
対する参照波形（表面エコー）との相関関数Ｆ1 （ｔ）
２８（Ｆ1 （ｔ）＝１／２００（Σn ＝１200 ｈ
1 （ｎ）×Ａ1 （ｎ＋ｔ）））を計算するとともに、該
高利得アンプからの出力信号と該信号に対する参照波形
（界面エコー）との相関関数Ｆ2 （ｔ）３０（Ｆ
2 （ｔ）＝１／２００（Σn ＝１200 ｈ2 （ｎ）×Ａ2
（ｎ＋ｔ）））を計算をする。上記２つの相関関数の最
大値間の時間差Δｔ1 を、あらかじめ試料を用いて測定
しておいた縦波音速で換算し、表層厚さを計算する。２
５が最大値時間検出部、２６が層厚さ計算部を示す。Correlation function F 1 (t) between the output signal from the low gain amplifier and the reference waveform (surface echo) for the signal.
28 (F 1 (t) = 1/200 (Σ n = 1 200 h
1 (n) × A 1 (n + t))), and the correlation function F 2 (t) 30 (F of the output signal from the high gain amplifier and the reference waveform (interface echo) for the signal)
2 (t) = 1/200 (Σ n = 1200 h 2 (n) × A 2
(N + t))) is calculated. The time difference Δt 1 between the maximum values of the two correlation functions is converted into the longitudinal wave sound velocity measured in advance using the sample, and the surface layer thickness is calculated. Two
Reference numeral 5 represents a maximum value time detection unit, and 26 represents a layer thickness calculation unit.
【００１９】また、相関関数計算により得られた２つの
関数に対し、更にその各々の関数の絶対値｜Ｆ1 （ｔ）
｜、｜Ｆ2 （ｔ）｜を取り、絶対値を取った２つの関数
の各の包絡曲線３１、３２を計算し、各々の包絡曲線の
最大値間の時間差Δｔ2 から、予め測定しておいた縦波
音速で換算し、表層厚さが測定される。For the two functions obtained by the correlation function calculation, the absolute value of each function | F 1 (t)
|, | F 2 (t) | is taken, the envelope curves 31 and 32 of the two functions whose absolute values are taken are calculated, and measured in advance from the time difference Δt 2 between the maximum values of the envelope curves. The surface layer thickness is measured by converting with the longitudinal sound velocity.
【００２０】[0020]
【発明の効果】以上の本発明により表層と内層で近似し
た組織の鋼種を組み合せた複層材料の表層厚さを、超音
波反射法により正確かつ効率よく検出することができ
る。また、複層材料の耐食性、耐摩耗性などを左右する
表層厚さを非破壊的に測定することが可能となり品質管
理、品質保証におおいに役立つ。As described above, according to the present invention, the surface layer thickness of a multi-layer material obtained by combining steel types having similar structures in the surface layer and the inner layer can be detected accurately and efficiently by the ultrasonic reflection method. In addition, the non-destructive measurement of the surface layer thickness, which influences the corrosion resistance and wear resistance of the multi-layer material, is possible, which is useful for quality control and quality assurance.
【図１】本発明の一実施例である複層材料の表層厚さ測
定方法の概要を示す説明図である。FIG. 1 is an explanatory view showing an outline of a method for measuring a surface layer thickness of a multilayer material which is an embodiment of the present invention.
【図２】本発明の上記複層材料の表層厚さ測定方法にお
いて、一実施例の動作を示すタイムチャートである。FIG. 2 is a time chart showing the operation of one example in the method for measuring the surface layer thickness of the multilayer material of the present invention.
【図３】本発明の上記複層材料の表層厚さ測定方法にお
いて、一実施例の参照波形を示す説明図である。FIG. 3 is an explanatory view showing a reference waveform of one example in the method for measuring the surface layer thickness of the multilayer material of the present invention.
【図４】従来の超音波パルス反射法を改良した２段階の
アンプを設ける方法の一例である。FIG. 4 is an example of a method of providing a two-stage amplifier that is an improvement of the conventional ultrasonic pulse reflection method.
【図５】従来の超音波パルス反射法を改良した２段階の
アンプを設ける方法の測定波形の一例である。FIG. 5 is an example of a measurement waveform of a method of providing a two-stage amplifier which is an improvement of the conventional ultrasonic pulse reflection method.
１ 複層材料 ２ 探触子 ３ 送信器 ４ 低利得アンプ ５ 高利得アンプ ６、７ Ａ／Ｄ変換ボー
ド ８ 同期部 ９ 内層 １０、１１ 表層 １２ 界面 １３ 水槽 １４ 水 １５ 表面エコーの伝播経路 １６ 界面エコーの
伝播経路 １７、１９ 低利得アンプ出力 １８ 高利得アンプ
出力 ２０ 同期信号 ２１、２２ 禁止ゲート発
生器 ２３ 保存部 ２４ 相関関数計算
部 ２５ 最大値時間検出部 ２６ 層厚さ計算部 ２７ デジタル信号Ａ1 （ｔ） ２８ 表面相関関数
計算Ｆ1 （ｔ） ２９ デジタル信号Ａ2 （ｔ） ３０ 界面相関関数
計算Ｆ2 （ｔ） ３１ ｜Ｆ1 （ｔ）｜の包絡曲線 ３２ ｜Ｆ2 （ｔ）
｜の包絡曲線 ３３ 低アンプ用参照データｈ1 （ｎ） ３４ 高アンプ用参照データｈ2 （ｎ） ３５、３６ 立上りパルス発生器 ３７厚さ測定器 ３８ 表示器1 Multilayer Material 2 Probe 3 Transmitter 4 Low Gain Amplifier 5 High Gain Amplifier 6, 7 A / D Converter Board 8 Synchronous Section 9 Inner Layer 10, 11 Surface Layer 12 Interface 13 Water Tank 14 Water 15 Surface Echo Propagation Path 16 Interface Echo propagation path 17, 19 Low gain amplifier output 18 High gain amplifier output 20 Synchronous signal 21, 22 Forbidden gate generator 23 Storage section 24 Correlation function calculation section 25 Maximum value time detection section 26 Layer thickness calculation section 27 Digital signal A 1 (t) 28 Surface correlation function calculation F 1 (t) 29 Digital signal A 2 (t) 30 Interface correlation function calculation F 2 (t) 31 | F 1 (t) | Envelope curve 32 | F 2 (t)
Envelope curve of | 33 Reference data for low amplifier h 1 (n) 34 Reference data for high amplifier h 2 (n) 35, 36 Rising pulse generator 37 Thickness measuring instrument 38 Display
Claims (2)
子と、探触子の出力信号を増幅するアンプが、低利得の
アンプと、その出力に時間ゲートをかけたのち高利得で
増幅するアンプを備えた表層厚さ測定手段を用いた複層
材料の表層厚さ測定方法において、 測定しようとする試料の表層材と同一材質、かつ表層厚
さとほぼ同一厚さの表面の滑らかな単相材から、前記低
利得アンプを用い予め採取した表面の信号を低利得アン
プ用参照データ、裏面の信号を高利得アンプ用参照デー
タとしてデジタル化して保存しておき、被測定試料に対
する低利得アンプ、高利得アンプの出力をそれぞれデジ
タル化して、それぞれに対応した前記参照データとの相
関関数計算をそれぞれに行い、それらの最大値を示す時
間の差と、予め求めてある音速を掛けて表層厚さを求め
ることを特徴とする複層材料の表層厚さ測定方法。1. A transmitter for transmitting an ultrasonic wave, an ultrasonic probe, and an amplifier for amplifying an output signal of the probe, wherein the amplifier has a low gain, and its output is time-gated and then a high gain. In the method for measuring the surface layer thickness of a multilayer material using the surface layer thickness measuring means equipped with an amplifier that amplifies with, the surface smoothness of the surface material of the sample to be measured is almost the same as the surface layer material. The single-phase material is used to digitize and store the front-side signal sampled using the low-gain amplifier as low-gain amplifier reference data and the back-side signal as high-gain amplifier reference data. The outputs of the gain amplifier and the high gain amplifier are digitized respectively, and the correlation function with the reference data corresponding to each is calculated respectively, and the difference in time showing the maximum value thereof is multiplied by the sound velocity obtained in advance. Surface layer thickness measurement method of the multi-layer material and obtaining a surface layer thickness.
める方法が、相関関数計算により得られた２つの関数に
対し、それぞれの関数の絶対値を取り、絶対値を取った
２つの関数のそれぞれの包絡曲線を計算して求めること
を特徴とする請求項１記載の複層材料の表層厚さ測定方
法。2. The method of obtaining the time at which the maximum value is obtained from the correlation function is such that the absolute value of each of the two functions obtained by the correlation function calculation is calculated and the absolute value of the two functions is calculated. The method for measuring a surface layer thickness of a multilayer material according to claim 1, wherein each envelope curve is calculated and obtained.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6035062A JP3043941B2 (en) | 1994-03-04 | 1994-03-04 | Surface thickness measurement method for multilayer materials |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6035062A JP3043941B2 (en) | 1994-03-04 | 1994-03-04 | Surface thickness measurement method for multilayer materials |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07243838A true JPH07243838A (en) | 1995-09-19 |
| JP3043941B2 JP3043941B2 (en) | 2000-05-22 |
Family
ID=12431541
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6035062A Expired - Lifetime JP3043941B2 (en) | 1994-03-04 | 1994-03-04 | Surface thickness measurement method for multilayer materials |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3043941B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000171234A (en) * | 1998-12-03 | 2000-06-23 | Ishikawajima Harima Heavy Ind Co Ltd | Film thickness measuring method for spray deposit |
| CN112433217A (en) * | 2020-11-10 | 2021-03-02 | 广州市东儒电子科技有限公司 | Object thickness measuring method, device, system, equipment and medium based on ultrasonic waves |
| CN113358072A (en) * | 2021-06-03 | 2021-09-07 | 河南科技大学 | Ultrasonic measurement equipment and method for number of layers of plate |
-
1994
- 1994-03-04 JP JP6035062A patent/JP3043941B2/en not_active Expired - Lifetime
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000171234A (en) * | 1998-12-03 | 2000-06-23 | Ishikawajima Harima Heavy Ind Co Ltd | Film thickness measuring method for spray deposit |
| CN112433217A (en) * | 2020-11-10 | 2021-03-02 | 广州市东儒电子科技有限公司 | Object thickness measuring method, device, system, equipment and medium based on ultrasonic waves |
| CN112433217B (en) * | 2020-11-10 | 2024-05-14 | 广州市东儒电子科技有限公司 | Object thickness measuring method, device, system, equipment and medium based on ultrasonic wave |
| CN113358072A (en) * | 2021-06-03 | 2021-09-07 | 河南科技大学 | Ultrasonic measurement equipment and method for number of layers of plate |
| CN113358072B (en) * | 2021-06-03 | 2024-02-06 | 河南科技大学 | Ultrasonic measuring equipment and method for number of layers of plates |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3043941B2 (en) | 2000-05-22 |
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